This is a national stage of PCT application No. PCT/FI99/00873, filed on Oct. 20, 1999. Priority is claimed on that application, and on patent application No. 982271 filed in Finland on Oct. 20, 1998.
The present invention relates to a method and apparatus for forming a group of rolls from at lest two rolls of a paper, board or cellulosic material web.
In paper mills, the rolls exiting the paper machine are slit at a slitter-winder into rolls of narrower width according to customer order. The widths of the narrowest customer rolls vary in the range of 100-500 mm. For instance, in mills making printing paper grades, the roll widths of narrow rolls are typically from 180 mm to 400 mm, in cardboard mills from 350 mm to 500 mm and in the manufacture of roll cores from 100 mm to 300 mm.
Narrow rolls are delivered to the customer either individually wrapped or, typically, as two- or multi-roll packs containing 2-4 rolls protected by a common wrapper. The ratio of the roll maximum diameter to the roll width of the separately wrapped narrow rolls is typically about 2.5, because a higher diameter-to-width ratio would cause instability in the handling and shipping of the rolls. In practice, the narrowest width of single rolls is typically about 300-400 mm and the maximum diameter depending on the paper or board grade is about 1000-1800 mm. In the delivery of two/multi-roll packs, the rolls are advantageously wrapped end-to-end together immediately after they leave the slitter-winder, because their handling and shipping in bundled form is much easier. One method of connecting the rolls to be packed together is to insert through their center bores a common inner core that holds the rolls of the pack together. Another commonly used method is to thread a reinforced plastic band through the roll center bores and about their perimeter, thus strapping the rolls into a tight pack. Damage to the edges of the outer rolls of the pack can be prevented by placing protective corner pieces under the angles of the strap. A still further method to combine rolls into a pack is to enclose the roll pack in a stretch-film wrap. Board rolls may also be bundled together using a self-adhesive tape wrap. If the rolls to be bundled are picked from separate sets of rolls, the adjacent rolls in pack may have different outer diameters, which can cause problems in the insertion of the connecting inner core as well as in the transport, wrapping and truck handling of the roll pack. Therefore, the rolls having a larger diameter are often calibrated by stripping off outer layers from the periphery of the roll prior to their bundling into multi-roll packs.
A method and apparatus for forming a group a group of rolls of paper, board or cellulosic material web. The method comprises separating apart form each other the rolls (3, 4, 5, 6, 7) of a roll set received from said slitter-winder (1), and combining desired rolls (3, 4, 5) of the roll set into a multi-roll pack. At least one of the desired rolls (3, 4, 5) to be included in the multi-roll pack is taken apart from the other rolls (6, 7) of the roll set resting on a conveyor (8, 9) and is moved to a waiting station (10) and is then moved back form the waiting station (10) onto the conveyor (9) in a manner allowing the desired rolls (3, 4, 5) of the multi-roll pack to be stored into a desired order having the adjacent ends of the rolls facing each other.
It is an object of the present invention to provide a method and an arrangement suited for handling rolls to be packaged into two- or multi-roll packs by automatically picking desired rolls apart from other rolls of a set, sorting the desired rolls into a desired order and placing said rolls abutting end-to-end each other prior to their bundling into a multi-roll pack.
In an embodiment according to the invention, the rolls leaving the slitter-winder are first separated from each other, e.g., by means of stop gages on the downward ramp following the slitter-winder or, alternatively, at the cross-over point of two conveyors located after the slitter-winder, whereupon at least some of the narrow rolls to be bundled into two- or multi-roll packs are taken apart from the other rolls of the sequence of rolls transported by the conveyor system and directed to a waiting station which is located alongside the conveyor and from which the rolls are transferred at a desired instant back onto the conveyor. Another function of the waiting station is to serve in the sorting of the rolls into a desired order. Next, the rolls can be combined into a pack, e.g., in a separate grouping station. From the grouping station, the bundled pack of rolls continues its travel in the packaging system.
The invention offers significant benefits.
By virtue of the invention, the tedious and time-consuming task of manual handling of rolls to be bundled into a two- or multi-roll pack can be eased substantially. Simultaneously, the capacity of the roll handling system is increased and risky situations in mill operation are reduced. Furthermore, the entrance to the slitter-winder can be protected by a fence, for instance, inasmuch as human attendance within the slitter-winder area becomes unnecessary under normal conditions.